Progrees and pifalls in organic aciduria

Organic acidurias comprise many various disorders. Methylmalonic and propionic acidurias are the most fre- quent diseases and the two organic acidurias for which we have the most important view on the long term out- come. Patients affected with these disorders mostly present in the neonatal period with a neurological distress of the intoxication type with ketoacidosis and mild to moder- ate hyperammonaemia. As neonates they most often require emergency treatment with supportive care, toxin removal procedures, high energy and free-protein nutri- tion. The mainstay of the long term management is a low-protein high-energy diet that is most often supple- mented with amino acids omitting the propiogenic ones. This diet must be completed with sufficient vitamins, minerals and micronutrients. Feeding problems are extremely common and these patients most often require enteral nutrition to maintain a good nutritional state. Specific additional therapies are usually used. L-carni- tine supplementation prevents from deficiency due to acyl-carnitine excretion. Metronidazole reduces propi- onate production in the gut. Sodium benzoate has been proposed to correct both chronic hyperammonaemia and hyperglycinemia.